Why Alien Life Would be our Doom – The Great Filter

Imagine NASA announced today
that they found aliens. Bacteria on Mars, weird alien fish
in the oceans of Europa, and also ancient alien ruins on Titan. Wouldn’t that be great? Well, no. It would be horrible news, devastating even. It could mean that the end of humanity
is almost certain and that it might be coming soon. Why? Why would the most exciting
discovery of our lifetime be bad? Let us imagine the development of life, from its inception to us today, as a flight of stairs. The first step is dead chemistry
that needs to assemble itself into self-replicating patterns,
stable and resilient, but also able to change and evolve. The second step is for our early life to
become more complex, able to build more complicated structures, and use the available energy
much more efficiently. On the next step, these cells combine
to become multicellular beings, enabling unbelievable variety
and further complexity. The step above sees the species
evolve big brains, enabling the use of tools, culture
and shared knowledge, which creates even higher complexity. The species can now become the
dominant lifeform on its planet, and change it according to its needs. First shy attempts to leave its
planet are happening. This is where we are now. It’s in the nature of life as we know it to reach out, to cover every
niche it can. And since planets have a limited
carrying capacity and lifespan, if a species wants to survive, it will look for more places
to spread to. So the steps above the current
ones seem logical: colonize your own solar system, then spread further to reach
other stars, to the possible final step:
becoming a galaxy-wide civilization. It’s very likely that this is a universal
principle for civilizations, no matter where they’re from. If a species is competitive and driven
enough to take control over its planet, they’ll probably not stop there. We know that there are up to 500 billion
planets in the Milky Way, at least 10 billion Earth-like planets. Many have been around billions
of years longer than Earth. But we’re observing zero
galactic civilizations. We should be able to see something… …but there’s nothing. Space seems
to be empty and dead. This means something is preventing living
things from climbing the staircase, beyond the step we’re on right now. …Something that makes becoming
a galactic civilization extremely hard, maybe impossible. This is the Great Filter. …A challenge or danger so
hard to overcome, that it eliminates almost every
species that encounters it. There are two scenarios: One means we are incredibly
special and lucky, the other one means we are doomed
and practically already dead. It depends on where the filter
is on our staircase: behind, or ahead of us? Scenario 1: Scenario 1:
The filter is behind us. We are the first. If the filter is behind us, that means that one of the steps we passed is almost impossible to take. Which step could it be? Is life ITSELF extremely rare? It’s very hard to make predictions
about how likely it is for life to emerge from dead things. There is no consensus. Some scientists think it develops everywhere
where the conditions are right; others think that Earth might
be the ONLY living place in the universe. Another candidate is the step
of complex animal cells. A very specific thing happened
on this step, and as far as we know, it happened
exactly once. A primitive hunter cell
swallowed another cell, but instead of devouring it,
the two cells formed a union. The bigger cell provided shelter, took care of interacting with the
environment and providing resources, while the smaller one used its
new home and free stuff, to focus on providing a lot of extra
energy for its host. With the abundant energy, the host cell
could grow more than before and build new and expensive things
to improve itself, while the guest became the
powerhouse of the cell. These cells make up every
animal on the planet. Maybe there are billions of bacteria-covered planets in the Milky Way, but not a single one, apart from us, has achieved our level of complexity. …or intelligence. We humans feel very smart and
sophisticated with our crossword puzzles and romantic novels. But a big brain, is first and foremost, a very expensive evolutionary investment. They are fragile, they don’t help in a fistfight with a bear, they cost enormous amounts of energy, and despite them, it took modern humans, 200,000 years to get from sharp sticks
to civilization. Being smart does not mean you get
to win automatically. Maybe intelligence is just not so great, and we’re lucky that it worked out for us. Scenario 2: Scenario 2:
The filter is ahead of us. Plenty of others died already. A Great Filter before us is orders of magnitude more dangerous than anything we encountered so far. Even if a major disaster killed most of us or threw us back thousands of years, we would survive and recover. And if we can recover, even if it takes a million years, then it’s not a Great Filter, but just a roadblock to an eventual galactic civilization. On universal timescales, even millions of years are just the blink of an eye. If a Great Filter really lies before us, it has to be so dangerous, so purely devastating and powerful, that it has destroyed most, if not all, advanced civilizations in our galaxy over billions of years. A really daunting and depressing hypothesis is that once a species takes control over its planet, it’s already on the path to self-destruction. Technology is a good way to achieve that. It needs to be something that’s so obvious, that virtually everybody discovers it, and so dangerous, that its discovery leads almost universally to an existential disaster. A large-scale nuclear war, nanotechnology that gets out of control, genetic engineering of the perfect super bug, an experiment that lights the whole atmosphere on fire. It might be a super-intelligent AI that accidentally (or purposely) destroys its creators. Or things that we can’t even see coming right now. Or it’s way simpler: species competitive enough to take over their planet necessarily destroy it while competing with each other for resources. Maybe there are runaway chain reactions in every ecosystem that once set in motion, are not fixable. And so once a civilization is powerful enough to change the composition of its atmosphere, they make their planet uninhabitable 100% of the time. Let’s hope that that’s not the case. If the filter IS ahead of us, our odds are really bad. What we can hope for. THIS is why finding life beyond Earth would be horrible. The more common life is in the universe, and the more advanced and complex it is, the more likely it becomes that a filter is in front of us. Bacteria would be bad, small animals would be worse, intelligent life would be alarming. Ruins of ancient alien civilizations… would be horrible. The best case scenario for us right now is that Mars is sterile, that Europa’s oceans are devoid of life, and the vast arms of the Milky Way harbor only empty oceans hugging dead continents. …That there are billions of empty planets waiting to be discovered and to be filled up with life. Billions of new homes… waiting for us… to finally arrive. How likely is it that we’ll find life outside of Earth that is similar to us? Well, that depends on how many planets there are out there in their star’s Goldilocks Zone– the area around the star where water can be liquid. Because stars come in all sizes and configurations, this zone is different for every star system and requires a little bit of physics to figure out. If that sounds like fun to you, this quiz from Brilliant helps to break down the maths for exactly how this is calculated. Brilliant is a problem-solving website that teaches you to think like a scientist by guiding you through problems. They take concepts like these break them up, into bite-sized bits present clear thinking in each part, and then build back up to an interesting conclusion. If you visit brilliant.org/nutshell or click the link in the description, you can sign up for free and learn all kinds of things. And as a bonus for Kurzgesagt viewers, the first 688 people will also get 20% of their annual membership. And if you DO find life on other planets, it may be wise to leave them alone for a while.

Comments 100

  • There's brand new stuff in the Kurzgesagt Merch Shop. Check it out here: shop.kurzgesagt.org

  • Since we already have so many structures and evidence of our existence send out into space (satellites, space stations, ships but also artefacts like the disc with mathematical information about earth) it would be likely if there would have been millions of other life forms before us that we would have found something similar

  • 1:16 BIG BRAIN

  • So what I'm hearing is …


  • "All we see is dead space"
    Isaac takes out his plasma cutter

  • Oooooo, so like if there was other intellegent life we wud have to compete or be outmatched xd. OOOF

  • I hate to break it to you, but it looks like we are gonna destroy ourselves.

  • It’s the Sayans.

  • It's in our nature to reach out. It's not necessarily in the nature of other life to reach out.

  • If the Great Filter exists it would definitely be behind us. If the great Filter was ahead of us then their would be other planetary species that we could observe. Personally I believe there is no filter, I think the monstrous size of the universe limits what we can and can not see. Even if human could travel at the speed of light we could really only travel 40ish light years in any direction. That isn't very far…

  • If such filter exist how do you know that ALL civilizations agree with this? If Such thing existed how do you know that no one ever put an stop to it, and that the reason whe hadn't been contacted is because someone made it illegal in order to it never happen again?

  • Nobody:

    Life at 1:16 : YEAH THIS IS BIG BRAIN TIME

  • if you believe god aliens exist

  • Technology destroys the earth before it allows us to leave it

    Could be global warming, AI, nuclear war, Kessler syndrome, ect.

  • Maybe there is an intergalactic organization regulating how planetary systems can interact with others. Maybe one of their rules is not to interfere with less advanced civilizations. It is just as we don't interfere with those tribal people living in the Amazon.

  • Is anyone now thinking about how small and insignificant we are?

  • 9:00 why is your cursor so big

  • if its ahead of us were next..

  • Some advice for Kurzgesagt writers: When writing about quite speculative topics, use less certain language.

  • 3:41 no it isn't. You just won't admit how unlikely it was for life as we know it to have started existing.

  • I refuse to believe we can’t move past this. I know we will, and find extraterrestrial intelligence on the way

  • Why should we be able to see whether other star systems are inhabited?

  • 1:15 BIG BRAIN

  • Maybe the contact or finding Aliens is the Great Filter and it depans from us, if We will Pass him or Not. Maybe We must destroy them or make Peace with them.

  • If there was such a thing. People would unite, and defend their own races, because we have new enemies..

  • What if human started doing something useful instead all of these humanity jokes.

  • If the universe is a computer simulation made by us, would it not be made without aliens?

  • Anyone else depressed that humans have achieved amazing things and if we could unite we can explore our galaxy and and beyond but we are stupid enough to only have wars with our own species

  • Spore reference! So happy

  • 1:16 BIG BRAIN

  • Life can be quite varied and diverse. tbh, the sea needs to be better explored and the earthen layers fully addressed before we move on to space imo.

    If we can't even build & have bodies that adapt properly under a high pressure sea atmosphere that's right next door, then humanity isn't ready for anything space has to offer.

    Terra-forming continents to better cover the expansive ocean? Pfft. Not even on anyone's agenda.

    If humanity can't even bother to debunk communication barriers & promote higher intelligence in other living beings (, species that don't fall under the homo sapient spectrum) on this shared planet, then humanity is far from ready to come into contact with other life forms.

    Humanity just seems like a spoiled obese pre-teen that not only needs to hit the gym, but also adapt a healthier mentality to treat others kinder than they do themselves.

    The internet is the only place that offers a united front that represents decent 'globalization', but the current governing countries and political systems are too slow to keep up.
    Even then, toxicity is abound among anything that relates to 'Political Correctness', Competitive E-Sports, and culture.
    Individuals rather argue points rather instead of respectfully discussing topics in order to reach a concrete conclusion free from bias.
    Truth, honesty, loyalties and virtue are all but fables in the common era to be spoken of akin to chivalry and etiquette.

    Humanity is does not meet the prerequisites.
    Humanity is not worthy.
    This is my fair and rightful judgement (and also my educated opinion.)

  • 0 civilizations? Michio kaku found a couple higher type ones already. Better research Kurzgesagt.

  • 4:00.. once? Happened for all animals individually. Just on earth..

  • 5:13 someone needs to look at the sumerian king lists, its background of what a char is and who the annunaki were and relics archeologists have uncovered, like that 400 million year old pickaxe which has wood that started turning into coal.. and other things

  • Caveman: starts fire

    Hairy boi did big brain tings

  • Hey Kurzgesagt, I'm thinking something. What if this great filter doesn't have to necessarily "stop" civilizations. You said anyone would want to spread everywhere, but obviously the better places instead of the worse places are chosen, right? We're looking at quantum psychs, higher dimensions, etcetera. What if there's a better option that every highly advanced situation has chosen?

  • 8:20 when you see a vagnal for the first time

  • Are we just gonna not talk about the alien doing a sick bong rip at 7:31?

  • Other life forms could also pass through a great filter, and we could, so what scares people?

  • Just nuke the filter out the way!

  • You seem to fall into the same trap as everyone else, we are NOT living on a FIRST generation planet or solar system, why does the generation of stars matter, because when a star explodes is when it creates some of the materials, those won't exist without a star exploding, so a star system not build from previous generations can't create life.

    There is no way that anyone can have a galaxy spanning empire, because life couldn't have existed that long. We are possible the first generation that can create GSE's.

    Life couldn't have been created for the past 13 billion years, it required billion years for stars to be born and die.

  • We had an entire Nicktoon in the 90s about aliens and Doom, we know its bad

  • The movie "Life (2017)" portrays it really well…

  • BiG BRaiN

  • Before the science become popular.. a bible says . The life is only on earth..

  • Good news I found a marker that orders me to make more markers.


  • Alien would make a world better because they have big brain
    We made fortnite and thats disappointing
    Aliens made minecraft and that really changed life

  • No one ever seems to consider that it would take just one highly technologically advanced alien civilization to completely change the appearance of the entire visible universe from our perspective. Or at least alter it extensively. In other words, we're being kept in the kiddie pool.

  • So raiders finding aliens in area 51 is a bad thing…

  • Me: Aliens could be cool, like Men in Black!
    Kurzgesagt: Just leave them alone
    Let's storm Area 51!🌌👽

  • B I G B R A I N

  • Chinas 9000 dash line

  • finding intelligent life more advanced than us would be the worst thing that could happen to us, the best thing would be to find remains of an advanced civilization that can be studied and learned.
    If we find an advanced civilization, it would be like the countries before the European Union and the ONU, the universe is reigned by anarchy, they will probably take whatever they want from us or do whatever they want and since we are weaker we would not have any chance to defend ourselves or say "No". Simple but thats how it works.

    Finding remains that we can study could lead us to not only colonies and interstellar travel but also to have a real POWER in case another intelligent life contacts us and not
    depend on goodwill or moral from them.

  • I don’t care if finding alien life would doom our race, It’s just more comforting knowing we’re not alone in our universe

  • First 1:30 I ignored….

  • I’ve fucked up its 11 and I gotta get up but I’m in a cycle of constantly clicking on these vids

  • The filter is ignorance, any alien species thats smilar to humans will be their own problem. Humans are stupid . So chances are any other intelligent life is the same lol

  • The Filter is multicelular life.

  • Looks like someone made a wall and made us pay for it. 😐

  • Or perhaps we are living inside an organism like a virus and all other lifeforms are getting destroyed by a defense mechanism like in our own bodies.

  • I got this idea from the novel Three Body, so that is why I take out every civilization I meet when I play stellaris

  • why do you think all life needs water , oxygen and carbon

  • scenario 3: we're all inside a galactic prison lmao

  • Huh, maybe that's why all other planets are uninhabitable… The other species already goofed their own planets with pollution and died out………………………. Okay yeah that is a bit of a stretch I'm not gonna lie.

  • Creeper (great filter) aw man

  • ill call it The Gr8 M8

  • Jumping to such an extreme conclusion with a sample size of 1 is pretty dumb.

  • it’s totally gonna be climate change

  • Why is it important for you to find life outside that is similar to us? When you don't limit yourself to find a life that is similar to us, but you are searching for life in all its possible forms, which we, of course, don't know, then you don't need bullshit like habitable zones and liquid water and firm ground and atmoshere, etc. These all are just our assumtions, but they don't need to be necessarily all true.
    Every video I see, every text I read says the same thing. You all are just repeating yourself, repeating the same hackneyed bullshit, you all are making the same mistakes over and over again, but basically nobody tries to see the bigger picture. The bigger picture is that we actually don't know what life is and thus don't know what are all the forms that life could manifest itself in the Universe. There is a definition of life. In fact there are more then one. I think the thermodynamic – the most general one is the best. But the problem is (at least for someone) that with this thermodynamic definition of life, life could be literally everywhere in the Universe and all those stupid concepts such as goldilocks/habitable zones would quickly become nonsensical (not that they already aren't). With this definition of life, you wouldn't look for just biological beings, but all beings! You wouldn't look in enviroments with water, but in all kinds of environments! Do you understand what I mean?

  • Your video is misleading for 12,334,101 humans due your primitive way to look at life.
    We exist today due to compassion not because we have continuously smashed our skulls through the history.
    As a hole the more you share the longer you survive.

  • Bruh the great filter is our own consiouness thats all no need to waste our time here😂.

  • Where i disagree is the idea of technology. Advances and new inventions could make us able to jump over that wall. For us in 2019, it seems hard. But imagine if 20 CRAZY new inventions came out before 2100? Perhaps machines that can absorb carbon and dump out oxygen like plants to halt global warming. An easier invention for the production of electric or solar cars. Look at the 1890's for example. London, Paris, Berlin were smoggy and gross from the heavy coal factories. After several new inventions like nuclear power, electric power, generators, now those cities are cleaner. Give it another 50 years to 2069, we may even have BETTER stuff.

  • Love this. How potentially scary, or ultimately inspiring.. no way to know, we gotta just keep on truckin'…

  • too many questions need answers and the answer usually with the one that create all this 🧐

  • i can't understand why all of this exists in the first place 🤪🤯

  • When you said "Itself", I thought you said "It-cells" to make a pun.

  • Better not storm Area 51 after all….

  • Either we are alone in this universe or we are not.
    Both are equally terrifying.

  • I dont like these videos. To think on how far we can go makes me sad. To think that I won't be able to experience it. Me not being able to experience the sight of going to planet to planet. I'll hope that humans will make it there but I like thinking on what's around me and living in the now and thinking about what is possible for me instead of thinking of what is impossible for me.

  • If we send humans at mars, some years later they will be aliens to us. They would have evolved to the conditions of Mars and they would look diferent.

  • No. We're going to go Mass Effect.

  • We have found aliens there are aliens 👽 In Area 51

  • Thanks i'm having an existential crisis again

  • Maybe the Milky Way civilization is everywhere.

    But because of communication and time issues

    They lost communication with each other, so they evolved separately.

    They may have emigrated in other galaxies, but they have evolved as described above.

  • We humans are our great filter…

  • And the Great Filter for the terrestrial planet with an active hydrosphere orbiting a G-Type main sequence star in Alpha Quadrant of the Milky Way is…..Feminism.

  • 1:15. BIG BRAIN

  • Who is in favor to remove the Great filter? 🙋‍♀️🙋‍♂️🙋‍♂️🙋‍♀️

  • I like how he stated that symbiosis only occured once, they are tons of animal species who use other animals to live, without one the other surely would die or have a horrid time adapting.

  • objective: become a galactic civilization
    obstacle: c l i m a t e c h a n g e

  • I want to see what alien bacteria looks like, just finding alien cells would be so interesting.

  • No stop stop stop the video right now, the reason why we are the only life is because of God my guy simple, we might just be the only thing apart of his plan

  • I think one day there will be a big desperation for food and adequate climates to grow food. The choice will be to either spend money on wars over climates, or spend the money on intergalactic travel to discover new climates. And that choice may actually be the filter whether a species makes it or not

  • Imagine if earth becomes like the really bad black market sort of planet in the future, a wasteland where life originated but never truly prospered, we would respect it as humanities mother planet but not as a place to really live in anymore

  • Kurzgesagt, destroying dreams one video at a time.

  • Humanity shall conquer the galaxy!

    Unless that great filter is ahead of us, if so enjoy your life to the fullest because the people 100 or more years from now aren’t.

  • I hope we can become advanced enough to reverse the destruction of our planet before we try to colonize other planets. With renewable energy and fusion energy it seems reasonable that we could do it.

  • I remember u mention on the other video that there's maybe a superior being that is great filter itself. superior being that watching us and then annihilate us when our technology advances enough.

    in my opinion, that is the most likely scenario. I kinda confused why u didn't mention it on this great filter video.

  • We are the great filter, humanity its self. how can we pass the great filter when we are selves are the filter. we are killing our selves very slowly.

Leave a Reply

Your email address will not be published. Required fields are marked *